Double safety magnetic valve

ABSTRACT

A double safety magnetic valve with two valves being accommodated in a housing, both axially displaceable valve disks thereof are disposed coaxially to, one another and each lifts from its respective valve seat through an axial movement in opening direction against the spring pressure of a first and second closing spring respectively, wherein the second, in flow direction of the double safety magnetic valve inner valve disk comprises as adjustment element a magnetic armature and the first, i.e. outer valve disk is motion-coupled with the inner valve disk in opening direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed generally to a double safety magneticvalve and more particularly to a double safety magnetic valve with twovalves being accommodated in a housing.

2. Description of Background of the Invention

A double safety magnetic valve of this kind became known, for example,by the DE 195 25 384 A1. Such double safety magnetic valves are used inparticular as safety magnetic valves on the gas input side of gas heatgenerators.

In the double safety magnetic valve known from the DE 195 25 384 A1 thetwo valve disks are disposed axially on top of one another in a housingand each cooperates with its own valve seat. The valve disks are eachpart of two adjustment elements independent of each other, the second ofwhich is guided axially displaceably in the first. Both adjustmentelements are opened by a common magnetic drive each against the actionof a closing spring, wherein the two closing springs perform the closingstroke of both valve disks completely independent of one another whenthe magnet is switched off. Thus the safety requirements for gas safetyvalves can be met.

Although a compact construction has been enabled with the known doublesafety magnetic valves and thus on one hand a space-saving and on theother hand substantially cheaper producable unit, the axial overallheight is still relatively large due to the valve disks and adjustmentelements which are axially displaceable as well as disposed behind oneanother. Due to the ever increasing miniaturization, generally a furtherreduction of dimensions of the known double safety magnetic valve and inparticular of its axial height is aimed at. Furthermore, mounting of theknown double safety magnetic valve is very difficult since the valvedisk, being the second one in flow direction of the double safetymagnetic valve, must be threaded through the valve opening of the firstvalve disk.

It is hence the object of the invention to design a double safetymagnetic valve of the aforementioned type even more compact in axialdirection (opening direction).

SUMMARY OF THE INVENTION

According to the invention this object is solved in a manner which isequally surprisingly simple and effective in that the outer (first)valve disk, being the first one in flow direction of the double safetymagnetic valve, surrounds the inner (second) valve disk and both theirvalve seats are combined to a common valve seat, which surrounds theonly valve opening, and the second (inner) closing spring of the inner(second) valve disk is supported on the outer (first) valve disk or onan adjustment element thereof.

In contrast to the double safety magnetic valve known from the DE 195 25384 A1, two valve seats do not have to be machined with high expenditureof time and labor, but only one single valve seat. Mounting of thedevice becomes easier since the parts do not have to be brought near totwo seats and a smaller device can be more easily handled. The inventivedouble safety magnetic valve can be produced cheaper since lessmachining occurs and the dimensions become smaller. In addition to theaxial overall height being drastically reduced, the flow values throughthe inventive double safety magnetic valve (multi-functional armature)become comparable to those of a single seat valve due to the inventivereduction of both valve functions to a common seat. The inventive doublesafety magnetic valve can be extended to all sizes and all kinds ofvalves, hence with the same housing a series with several variants canbe realized, for example, single magnetic valve, double magnetic valve,or multi-functional valve with various regulators.

The inner (second) closing spring of the inner (second) valve disk issupported on the outer (first) valve disk or on the adjustment elementthereof, for example on a peripheral shoulder or on the base of theadjustment element of the outer (first) valve disk. The inner (second)closing spring can, for example, be disposed between the two adjustmentelements, perferably in an annular gap or in an opening of the innermagnetic armature open in opening direction.

Naturally, the invention is not limited to two valves or valve disks,but can be used also for three or more valve disks disposed coaxially,which are nested into one another.

In an advantageous development of this embodiment a common flat bearingsurface for both valve disks is provided on the common valve seat. Thismeasure has the advantage that both valve seats can be produced in asingle process by machining of the common, in particular flat bearingsurface or bearing surface without steps.

In an alternative development two axially off-set bearing surfaces canbe provided on the common valve seat for one valve disk respectively.For example, both valve seats can be constructed on different planes onthe common valve seat.

For an optimal sealing effect, for a flat bearing surface an elastomersealing means of the valve disk cooperating with said flat bearingsurface is pointed or for a pointed bearing surface a sealing means ofthe valve disk cooperating with said pointed bearing surface is flat.All variants of the seat arrangement are possible, for example bothpointed, both flat, both on the same axial height, both axially off-setto one another, each also vice versa, etc.

Further, particularly preferred are such developments of the doublesafety magnetic valve where a bearing surface for an adjustment element(regulator element) of a flow regulator, with the adjustment elementbeing axially moveable in the valve opening, is also provided on thecommon valve seat. This measure has the advantage that three functions(two valves and one flow regulation) are brought together on one seat.The closed position of the adjustment element in the valve opening canbe exactly defined by bearing on the common valve seat. The adjustmentelement can for example be a rod, the free diskshaped end of whichextending into the valve opening bears all around on the common valveseat in the closed position.

In an alternative development a bearing or regulator surface for anadjustment element provided upstream in front of the two valve disks orvalves can be provided on the common valve seat. In particular if theadjustment element engages over both valve disks in a pot-shaped manner,they are additionally covered by the adjustment element.

In order to be able to check the tightness of the inventive doublesafety magnetic valve a sealing check opening is provided on the commonvalve seat, which opens into the space between the two valve disks.

A separate guide of the inner valve disk or its adjustment disk can bedispensed with if the inner valve disk or the magnetic armature isguided axially displaceably within the outer valve disk or itsadjustment element or within a guide element of the outer valve disk.

It is particularly advantageous, if the outer valve disk ismotion-coupled with the inner valve disk in opening direction. Thus, theouter valve disk is also lifted from the common valve seat at the sametime with the inner valve disk. In closing direction, however, bothvalves are not motion-coupled, for them to be able to perform theirclosing lift completely independent from one another.

In a development of this embodiment the outer valve disk or theadjustment element thereof can engage behind the magnetic armature inopening direction.

In order to be able to produce the double safety magnetic valve withparticularly low production costs, the housing of the two valves isdesigned preferably as extruded profile or as a diecast part. For suchextruded profiles it is also possible to laterally attach the sealingcontrol required for gas safety valves.

Additional advantages of the invention can be gathered from thedescription and the drawing. Also, the previously mentioned and thefollowing characteristics can be used according to the invention eachindividually or collectively in any combination. The embodiments shownand described are not to be taken as a conclusive enumeration, but haveexemplary character for the description of the invention.

The invention is shown in the drawing and is more closely described bymeans of embodiments.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a first embodiment of the inventive double safety magneticvalve in a longitudinal section;

FIG. 2 shows an enlarged view of the double safety magnetic valve ofFIG. 1 in the region of its valve opening according to cut II; and

FIG. 3 shows in an enlarged view corresponding to FIG. 2 a secondembodiment of the inventive double safety magnetic valve, wherein theinner (second) closing spring is supported on the base of the outer(first) adjustment element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 a double safety magnetic valve is denoted with 1, the twovalves 2 and 3 thereof, which are circuited in series, are accommodatedin a common housing 4. This housing 4 is partitioned by a valve opening5 into a gas entry space 6 and a gas exit space 7, wherein the valveopening 5 is surrounded by a valve seat 8.

The first (outer) valve 2 on the input side, i.e., the first one in flowdirection of the double safety magnetic valve 1, consists of an annularfirst (outer) valve disk 9, an adjustment (actuator) element (hollowarmature or bushing) 10 connected to the valve disk 9 and a first(outer) closing spring 11. The second (inner) valve 3 on the output sideconsists of an annular second (inner) valve disk 12, a magnetic armature13 connected to this valve disk 12 and a second (inner) closing spring14.

The two valves 2,3 and their respective valve disks 9,12 are disposedcoaxially to one another with respect to a common axis 15, wherein theouter (first) valve disk 9 annularly surrounds the inner (second) valvedisk 12. The valve seat 8 serves with its bearing surface 8 a (FIG. 2)as common valve seat for both valve disks 9,12, which each lift by anaxial movement in opening direction 16 from the common valve seat 8. Acommon magnetic drive 17 with a magnetic coil 18 and a guide opening 19,in which the adjustment (actuator) element 10 is guided axiallydisplaceably, serves for opening the two valves 2,3. The magneticarmature 13 is itself guided axially displaceably in the adjustment(actuator) element 10, wherein the adjustment (actuator) element 10,which is designed pot-shaped, engages behind the magnetic armature 13 inopening direction 16 and is thus motion-coupled with the magneticarmature 13 in opening direction 16.

The outer closing spring 11 is supported on the housing 4, whereas theinner closing spring 14 is supported inside the adjustment element 10 ona peripheral shoulder 20. In the shown closed state of the double safetymagnetic valve 1, the outer closing spring 11 therefore supplies theforce for closing both valve disks 9,12 or both valves 2,3. Both valvesbecause the inner closing spring 14 supports itself against the outerclosing spring 11 which is thus relieved.

Magnetic force lines emerge when the magnetic coil 18 is excited, whichattract the magnetic armature 13 together with the inner valve disk 12in opening direction 16. Due to the motion-coupling, the outer valvedisk 9 is also lifted from the common valve seat 8 at the same time withthe inner valve disk 12. After switching off the magnetic coil 18 theclosing springs 11, 14 effect for each valve 2,3 a closing independentfrom one another. The force of the inner closing spring 14 closes theinner valve disk 12 or the inner valve 3.

In case the outer valve 2 does not close, for example because theadjustment element 10 is jammed in the guide opening 19, the innerclosing spring 14 is dimensioned such that nevertheless enough force ispresent for closing the inner valve disk 12 or the inner valve 3 in thiscase as well. This means that the inner valve 3 closes if the outervalve 2 closes (lift of the inner valve disk 12 relative to the outervalve disk 9: 1 mm) and if the outer valve 2 does not close due tomalfunctioning (lift of the inner valve disk 12 relative to the outervalve disk 9: nominal lift+1 mm). For opening of both valves 2,3 astronger magnet is not necessary compared with known double safetymagnetic valves having valves disposed axially behind one another,despite the stronger outer closing spring 11, since the outer closingspring 11, as described above, is relieved by the inner closing spring14.

In order to control the flow through the valve opening 5, an adjustmentelement (regulator element) 21 which is Y-shaped in cross-section isprovided which engages through the valve opening 5 and which is axiallydisplaceable. The adjustment element (regulator element) 21 is adjustedby means of a flow regulator 22 known per se according to an outputpressure desired in the gas exit space 7. In its closed position shownin FIG. 2, the adjustment element (regulator element) 21 also bears onthe flat bearing surface 8 a of the common valve seat 8 with its freedisk-shaped end, wherein the diameter of the disk-shaped end is largerthan the diameter of the valve opening 5.

In contrast to this first embodiment, in the double safety magneticvalve 101 shown in FIG. 3 the inner closing spring 114 is accommodatedwithin the opening (blind bore) 123 in the magnetic armature 113 andsupports itself at one end on the magnetic armature 113 and on the otherend on the base 124 of the pot-shaped adjustment element 110. Thisarrangement allows many possibilities for the spring dimensioning. Theadvantage of the dependently supported closing springs 111 and 114consists in that in case of jamming of the magnetic armature 113 in theadjustment element 110, the strong outer closing spring 111, which sofar stored the closing force for both valve disks 109, 112, closes theremaining intact outer valve disk 109.

In this embodiment, the common valve seat 108 does not comprise a commonflat bearing surface for both valve disks 109 and 112, but the twobearing surfaces 108 a and 108 b are disposed axially off-set to oneanother. The outer bearing surface 108 a is pointed and the elastomersealing means of the outer valve disk 109 is flat. In contrast, theinner bearing surface 108 b, which at the same time serves as bearingsurface for the adjustment element 21, is flat and the elastomer sealingmeans of the inner valve disk 112, which cooperates with this bearingsurface 108 b, is pointed. Furthermore, a sealing-check-opening 135 isprovided on the common valve seat 108, which leads into the annularspace between both valve disks 109,112, such that a sealing check of thedouble seat valve 101 is possible.

It is of course to be understood that various changes may be made to theembodiments of the double safety magnetic valve described above withoutdeparting from the scope of the invention. Additional advantages andmodifications which will readily occur to those skilled in the art fromconsideration of the specification and practice of the invention areintended to be within the scope and spirit of the following invention.

I claim:
 1. A double safety magnetic valve comprising: a housing: firstand second valves both being accommodated in said housing, where saidfirst and second valves further include first and second correspondingaxially displaceable valve disks which are disposed coaxially to oneanother and each lifts from its respective valve seat through an axialmovement in the opening direction against the spring pressure of a firstand second closing spring respectively, wherein: the first valve diskbeing the first one in flow direction of the double safety magneticvalve surrounds the second valve disk and both their valve seats arecombined to a single common valve seat, which surrounds the only valveopening, and the second closing spring of the second valve disk issupported on the first valve disk or on an actuator element that axiallymoves the first valve disk, the surface of the common valve seat betweenthe first and second valve disks being flat; the second valve diskfurther comprises a magnetic armature and the first valve disk ismotion-coupled with the second valve disk in the opening direction,wherein the magnetic armature is coupled to axially move the secondvalve disk in the closing direction independent of the first valve disk.2. The double safety magnetic valve according to claim 1, wherein acommon flat bearing surface for both valve disks is provided on thecommon valve seat.
 3. The double safety magnetic valve according toclaim 1, wherein two axially off-set bearing surfaces are provided onthe common valve seat for one valve disk respectively.
 4. The doublesafety magnetic valve according to claim 1, wherein for a flat bearingsurface an elastomer sealing means of the valve disk cooperating withsaid flat bearing surface is pointed or for a pointed bearing surface asealing means of the valve disk cooperating with said pointed bearingsurface is flat.
 5. The double safety magnetic valve according to claim1, wherein a bearing surface for a regulator element of a flowregulator, with the regulator element being axially moveable in thevalve opening, is also provided on the common valve seat.
 6. The doublesafety magnetic valve according to claim 1, wherein a bearing orregulator surface for a regulator element provided upstream in front ofthe two valve disks is provided on the common valve seat.
 7. The doublesafety valve according to claim 1, wherein a sealing check opening isprovided on the common valve seat, which opens into the space betweenthe two valve disks.
 8. The double safety magnetic valve according toclaim 1, wherein at least one of the second valve disk and the magneticarmature is guided axially displaceably within the first valve disk orthe actuator element or within a guide element of the first valve disk.9. The double safety magnetic valve according to claim 1, wherein thefirst valve disk or the actuator element engages behind the magneticarmature in the opening direction.
 10. The double safety magnetic valveaccording to claim 1, wherein the second closing spring is supported ona peripheral shoulder of the actuator element of the first valve disk.11. The double safety magnetic valve according to claim 1, wherein thesecond closing spring is supported on a base of the actuator element ofthe first valve disk.
 12. The double safety magnetic valve according toclaim 11, wherein the second closing spring is disposed in an opening ofthe magnetic armature which opening is open in opening direction. 13.The double safety magnetic valve according to claim 1, wherein thehousing of the two valves is designed as extruded profile or as diecastpart.
 14. A double safety magnetic valve comprising: a magneticarmature; a housing; first and second valves disposed in said housingand including first and second corresponding axially displaceable valvedisks disposed coaxially to one another, the first valve disksurrounding the second valve disk; a single valve seat common to boththe first and second valve disks and surrounding the only valve opening,each valve disk lifting from the single valve seat through an axialmovement in the opening direction against the spring pressure of a firstand second closing spring respectively; wherein: the magnetic armatureis coupled to axially move the second valve disk in the closingdirection independent of the first valve disk whereby the second valvedisk closes even when the first valve disk fails to close with thesecond valve disk; the first valve disk is motion coupled with thesecond valve disk in the opening direction; and the second valve disk issupported on the first valve disk or on an actuator element thatactuates the first valve disk.
 15. A double safety magnetic valvecomprising: a magnetic armature; a housing; first and second valvesdisposed in said housing and including first and second correspondingaxially displaceable valve disks disposed coaxially to one another, thefirst valve disk surrounding the second valve disk; a single valve seatcommon to both the first and second valve disks and surrounding the onlyvalve opening, each valve disk lifting from the single valve seatthrough an axial movement in the opening direction against the springpressure of a first and second closing spring respectively; wherein: thesingle valve seat has a flat surface and each valve disk has an annularpointed portion that abuts the flat surface of the single valve seat;the magnetic armature is coupled to axially move the second valve disk;the first valve disk is motion coupled with the second valve disk in theopening direction; and the second valve disk is supported on the firstvalve disk or on an actuator element that actuates the first valve disk.16. A double safety magnetic valve comprising: a magnetic armature; ahousing; first and second valves disposed in said housing and includingfirst and second corresponding axially displaceable valve disks disposedcoaxially to one another, the first valve disk surrounding the secondvalve disk; a single valve seat common to both the first and secondvalve disks and surrounding the only valve opening, each valve disklifting from the single valve seat through an axial movement in theopening direction against the spring pressure of a first and secondclosing spring respectively; wherein: the surface of the single valveseat has a flat annular portion and at least one of the first and secondvalve disks has a pointed annular surface that abuts the flat annularportion of the single valve seat; the magnetic armature is coupled toaxially move the second valve disk; the first valve disk is motioncoupled with the second valve disk in the opening direction; and thesecond valve disk is supported on the first valve disk or on an actuatorelement that actuates the first valve disk.